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Amid rumors his ex Gwen Stefani has moved on with Blake Shelton, her co-judge on "The Voice," Gavin Rossdale was spotted making out with a mystery brunette at the Operation Smile 2015 Gala on Oct. 2 in Los Angeles, reports RadarOnline.com.

According to the site, a source, who was seated at a table next to Gavin at the charity event, said that the Bush rocker brought a date, but tried to keep his distance at first.

"Gavin brought a beautiful tall brunette woman to the event and, at first, it seemed that it was his publicist or something," said the source.

The source added, "They came in together and sat next to each other at dinner, but made sure to keep their distance because they knew people were watching them."

But apparently the sexy Brit let the night work its magic and after dinner things got steamy.

"After drinks started flowing following dinner, Gavin followed her to the bathroom at the same time I was walking towards the restroom," the insider dished to Radar. "She left the restroom just before I did and when I walked out, Gavin and her were kissing!"

This is the first time we've heard rumors of Gavin moving on with another woman since Gwen filed for divorce on Aug. 3, 2015, after 13 years of marriage. The rock and roll couple have three sons, Kingson, Zuma and Apollo.